A mouse device is one of the widely-used computer peripheral input devices. When a mouse device is held by the palm of a user, the user may move the mouse device to control the movement of a cursor of the computer system. The mouse device complies with the intuitive operating habits of many users. Consequently, the mouse device is the most prevailing input device.
The structure and the function of a conventional mouse device will be described as follows. FIG. 1 schematically illustrates the connection between a conventional mouse device and a computer system. The computer system 100 comprises a computer host 101 and a display screen 102. The computer host 101 is in communication with a mouse device 1 and the display screen 102. The computer host 101 has a connecting port 1011. A graphic-based window 1021 and a cursor 1022 are shown on the display screen 102. The mouse device 1 is used for controlling the movement or operation of the cursor 1022. Consequently, the computer host 101 executes a corresponding command. The mouse device 1 comprises a casing 10, a left button 11, a right button 12, a scroll wheel 13, and a connecting cable 14. The left button 11 is disposed on the casing 10 and arranged beside a left side of the scroll wheel 13. In addition, the left button 11 is exposed outside the casing 10. When the left button 11 is pressed down, a left button signal is generated. Like the left button 11, the right button 12 is disposed on the casing 10 and arranged beside a right side of the scroll wheel 13. The right button 12 is also exposed outside the casing 10. When the right button 12 is pressed down, a right button signal is generated. The scroll wheel 13 is disposed within the casing 10 and partially exposed outside the casing 10. When the scroll wheel 13 is rotated by the user, a corresponding scrolling data is generated. After the scrolling data is transmitted to the computer host 101, the computer host 101 performs an operation of scrolling the graphic-based window 1021 upwardly or downwardly according to the scrolling data. The connecting cable 14 is disposed within the casing 10 and protruded outside the casing 10. When the connecting cable 14 is connected with the connecting port 1011, the communication between the mouse device 1 and the computer system 100 is established.
The conventional mouse device 1 comprises a switching module (not shown). By operating the switching module, the stepped motion in response to the rotation of the scroll wheel 13 is correspondingly changed. The structure of the switching module is known to those skilled in the art, and is not redundantly described herein.
When the switching module is operated to control the scroll wheel 13 to be in a stepped motion mode, the scroll wheel 13 is rotated for one graduation in response to one-unit rotation of the user. Consequently, the mouse device 1 generates a one-graduation scrolling data. After the computer host 101 receives the one-graduation scrolling data, the computer host 101 performs a one-graduation window scrolling function. When the switching module is operated to control the scroll wheel 13 to be in a non-stepped motion mode (i.e., a so-called hyper-fast mode), the scroll wheel 13 is continuously rotated for plural graduations in response to one-unit rotation of the user. That is, the scroll wheel 13 is rotated at a high speed. According to settings, the mouse device 1 realizes that the scroll wheel 13 is in the non-stepped motion mode. Consequently, the mouse device generates default high-speed scrolling data. After the computer host 101 receives the high-speed scrolling data, the computer host 101 performs a high-speed window scrolling function.
Nowadays, the demands on the rotating speed of the scroll wheel and the time length of continuously rotating the scroll wheel are increased. Therefore, there is a need of providing a scroll mouse capable of increasing the rotating speed of the scroll wheel and extending the time length of continuously rotating the scroll wheel.